#include <iostream>

#include <alsa/asoundlib.h>

 

int main()

{

       int                               rc;

       snd_pcm_t*                         handle;

       snd_pcm_hw_params_t*      params;

       unsigned int                  val, val2;

       int                               dir;

       snd_pcm_uframes_t             frames;

 

       if ( (rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0)) < 0)

       {

              std::cerr << "unable to open pcm devices: " << snd_strerror(rc) << std::endl;

              exit(1);

       }

 

       snd_pcm_hw_params_alloca(&params);

 

       snd_pcm_hw_params_any(handle, params);

 

       snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);

 

       snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE);

 

       snd_pcm_hw_params_set_channels(handle, params, 2);

 

       val = 44100;

 

       snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir);

 

       if ( (rc = snd_pcm_hw_params(handle, params)) < 0)

       {

              std::cerr << "unable to set hw parameters: " << snd_strerror(rc) << std::endl;

              exit(1);

       }

 

       std::cout << "PCM handle name = " << snd_pcm_name(handle) << std::endl;

 

       std::cout << "PCM state = " << snd_pcm_state_name(snd_pcm_state(handle)) << std::endl;

 

       snd_pcm_hw_params_get_access(params, (snd_pcm_access_t *)&val);

 

       std::cout << "access type = " << snd_pcm_access_name((snd_pcm_access_t)val) << std::endl;

 

       snd_pcm_hw_params_get_format(params, (snd_pcm_format_t*)(&val));

      

       std::cout << "format = '" << snd_pcm_format_name((snd_pcm_format_t)val) << "' (" << snd_pcm_format_description((snd_pcm_format_t)val) << ")" << std::endl;

 

      snd_pcm_hw_params_get_subformat(params, (snd_pcm_subformat_t *)&val);

      std::cout << "subformat = '" <<

    snd_pcm_subformat_name((snd_pcm_subformat_t)val) << "' (" << snd_pcm_subformat_description((snd_pcm_subformat_t)val) << ")" << std::endl;

 

      snd_pcm_hw_params_get_channels(params, &val);

      std::cout << "channels = " << val << std::endl;

 

      snd_pcm_hw_params_get_rate(params, &val, &dir);

      std::cout << "rate = " << val << " bps" << std::endl;

 

       snd_pcm_hw_params_get_period_time(params, &val, &dir);

      std::cout << "period time = " << val << " us" << std::endl;

 

      snd_pcm_hw_params_get_period_size(params, &frames, &dir);

      std::cout << "period size = " << static_cast<int>(frames) << " frames" << std::endl;

 

       snd_pcm_hw_params_get_buffer_time(params, &val, &dir);

      std::cout << "buffer time = " << val << " us" << std::endl;

      

       snd_pcm_hw_params_get_buffer_size(params, (snd_pcm_uframes_t *) &val);

      std::cout << "buffer size = " << val << " frames" << std::endl;

 

      snd_pcm_hw_params_get_periods(params, &val, &dir);

      std::cout << "periods per buffer = " << val << " frames" << std::endl;

 

       snd_pcm_hw_params_get_rate_numden(params, &val, &val2);

      std::cout << "exact rate = " << val/val2 << " bps" << std::endl;

      

      val = snd_pcm_hw_params_get_sbits(params);

      std::cout << "significant bits = " << val << std::endl;

 

      snd_pcm_hw_params_get_tick_time(params, &val, &dir);

      std::cout << "tick time = " << val << " us" << std::endl;

 

      val = snd_pcm_hw_params_is_batch(params);

      std::cout << "is batch = " << val << std::endl;

 

      val = snd_pcm_hw_params_is_block_transfer(params);

      std::cout << "is block transfer = " << val << std::endl;

 

      val = snd_pcm_hw_params_is_double(params);

      std::cout << "is double = " << val << std::endl;

 

       val = snd_pcm_hw_params_is_half_duplex(params);

      std::cout << "is half duplex = " << val << std::endl;

 

       val = snd_pcm_hw_params_is_joint_duplex(params);

      std::cout << "is joint duplex = " << val << std::endl;

 

       val = snd_pcm_hw_params_can_overrange(params);

      std::cout << "can overrange = " << val << std::endl;

 

      val = snd_pcm_hw_params_can_mmap_sample_resolution(params);

      std::cout << "can mmap = " << val << std::endl;

 

      val = snd_pcm_hw_params_can_pause(params);

      std::cout << "can pause = " << val << std::endl;

 

       val = snd_pcm_hw_params_can_resume(params);

      std::cout << "can resume = " << val << std::endl;

 

      val = snd_pcm_hw_params_can_sync_start(params);

      std::cout << "can sync start = " << val << std::endl;

 

      snd_pcm_close(handle);

 

      return 0;

}
